Directional long borehole hydraulic fracturing gas extraction technology and application in extra thick coal seam
In order to solve the problem of significant differences in permeability and gas storage in the ultra-thick coal seam of Dafosi Coal Mine,which seriously affects the replacement of mine extraction and extraction,a directional long borehole hydraulic fracturing technology of"segmented fracturing extension fracture + overall fracturing communication network"is proposed.By increasing the permeability of the coal seam,the efficiency of mine gas extraction is improved,and engineering application tests are conducted on the 40103 working face.A total of 4 directional long borehole segmented hydraulic fractu-ring constructions were completed,with a cumulative fracturing volume of 2190 meters,a maximum pumping pressure of 17.83 MPa,a cumulative fracturing water injection volume of 4535 m3,and a total fracturing time of 10853 minutes.Com-pared to pre-drilled holes without fracturing,the gas extraction concentration after fracturing increased by 2.20～4.22 times,and the extraction flow rate per100 meters increased by4.93～11.03 times.The experimental results show that the permeability characteristics of coal seams increase after hydraulic fracturing,and the gas extraction effect is significantly im-proved.It preliminarily confirms the applicability of long borehole hydraulic fracturing to enhancing gas extraction,providing technical support for efficient gas extraction in the Binchang mining area.
hydraulic fracturingextra thick coal seamdirectional long boreholepressure relief gasgas extraction
国家科技期刊平台
NSTL
万方数据
维普
